Achieving Colorful Ultralong Organic Room-Temperature Phosphorescence by Precise Modification of Nitrogen Atoms on Phosphorescence Units

作者：Huiwen Jin, Xue Zhang, Jiaxin Ma, Lijuan Bu, Chen Qian, Zewei Li, Yan Guan, Mingxing Chen, Zhimin Ma, Zhiyong Ma, Zhiyong Ma, Zhiyong Ma · 发表于：ACS Applied Materials & Interfaces · 年份：2023 · DOI：10.1021/acsami.3c14054 · 被引用次数：43 · 研究领域：Luminescence and Fluorescent Materials、Organic Light-Emitting Diodes Research、Advanced Sensor and Energy Harvesting Materials

We successfully tune ultralong organic room-temperature phosphorescence (UORTP) by a simple strategy of precisely modifying nitrogen atoms on Phosphorescence Units, and colorful ultralong phosphorescence can be achieved. We for the first time investigate the structure–function relationship between phosphorescence properties and molecular structures of Phosphorescence Units . With BCz and BCz-1 as comparison, eight new Phosphorescence Units were synthesized by introducing one or two nitrogen atoms to the naphthalene moiety. For all the 10 Phosphorescence Units, their room-temperature ultralong phosphorescence in the PMMA film should be assigned to monomer phosphorescence from intrinsic T 1 decay. For Phosphorescence Units series I (BCz, NBCz-1, NBCz-2, NBCz-3, NBCz-4, NBCz-5, and NBCz-6), introducing one nitrogen atom to the naphthalene moiety can significantly affect the phosphorescence properties of Phosphorescence Units, and the effect is quite complicated. For modification on the inner ring, the T 1 energy level of NBCz-1 decreases, and the red shift of UORTP occurs while the T 1 energy level of NBCz-2 increases and the blue shift of UORTP happens. For modification on the outer ring, no phosphorescence color change is observed for NBCz-3 and NBCz-4, but their phosphorescence lifetimes vary notably due to different intersystem crossing efficiencies; as the modification site approaches the central five-member ring, the T 1 energy levels of NBCz-5 and NBCz-6 decrease, and the...